The Biden administration has withdrawn the nomination of a leading law professor to an international human rights post, for describing Israel as an “apartheid state” and accusing the top Democrat in Congress of being “bought” by pro-Israel groups.

James Cavallaro, of Wesleyan and Yale universities, said he was told by the US state department on Tuesday it had dropped his selection to the Inter-American Commission on Human Rights (IACHR) “due to my statements denouncing apartheid in Israel/Palestine”.

The withdrawal of his nomination followed an article by a New York Jewish newspaper, the Algemeiner, that also highlighted Cavallaro’s retweeting of a Guardian story about the gratification of pro-Israel groups at the election of the New York Democratic congressman Hakeem Jeffries as House minority leader.

Jeffries is closely tied to the American Israel Public Affairs Committee (Aipac) and other hardline pro-Israel lobby groups. One of them, Pro-Israel America, was his largest single donor over the past year.

Cavallaro retweeted the Guardian story with the comment: “Bought. Purchased. Controlled.”

The state department spokesman, Ned Price, said the administration had not been acquainted with Cavallaro’s views when his nomination was announced on Friday.

“We were not aware of the statements and writings,” he said. “His statements clearly do not reflect US policy, they are not a reflection of what we believe and they are inappropriate to say the least.”

Cavallaro, who was IACHR president six years ago, said he reminded state department officials that Human Rights Watch, Amnesty International and the leading Israeli human rights group, BTselem, “have issued reports naming the conditions in Israel/Palestine as apartheid”.

“My nomination would not have affected US policy on Israel. What has the withdrawal of my nomination achieved? The removal from the [IACHR] of the potential return of a committed, experienced advocate for human rights in the Americas,” he said on Twitter.

Cavallaro described the withdrawal of his nomination as part of broader “censorship of human rights advocates who denounce apartheid in Israel”, making reference to the Harvard Kennedy School’s blocking of a post for the former Human Rights Watch director Kenneth Roth over his criticisms of Israeli policies. The school backed down following a public outcry.

Cavallaro, the founder and director of the University Network for Human Rights, said he deleted “many” of his controversial tweets because he was “proactively and in good faith addressing concerns the state department had raised during the vetting process about public expressions of my personal views on US policy”.